A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
jos 16:1THE GENERAL BORDERS OF THE SONS OF JOSEPH. (Jos 16:1-4)
the lot of the children of Joseph fell--Hebrew, "went forth," referring either to the lot as drawn out of the urn, or to the tract of land thereby assigned. The first four verses describe the territory allotted to the family of Joseph in the rich domains of central Palestine. It was drawn in one lot, that the brethren might be contiguously situated; but it was afterwards divided. The southern boundary only is described here; that on the north being irregular and less defined (Jos 17:10-11), is not mentioned.
water of Jericho-- (Kg2 2:19), at the joint of its junction with the Jordan.
mount Beth-el--the ridge south of Beth-el. Having described the position of Joseph's family generally the historian proceeds to define the territory; first, that of Ephraim.
jos 16:5THE BORDERS OF THE INHERITANCE OF EPHRAIM. (Jos 16:5-9)
the border of their inheritance . . . was Ataroth-addar--Ataroth-addar (now Atara), four miles south of Jetta [ROBINSON], is fixed on as a center, through which a line is drawn from Upper Beth-horon to Michmethah, showing the western limit of their actual possessions. The tract beyond that to the sea was still unconquered.
jos 16:6Michmethah on the north side--The northern boundary is traced from this point eastward to the Jordan.
jos 16:8from Tappuah westward unto the river Kanah--It is retraced from east to west, to describe the prospective and intended boundary, which was to reach to the sea. Kanah ("reedy") flows into the Mediterranean.
jos 16:9separate cities for the children of Ephraim were among the inheritance of Manasseh-- (Jos 17:9), because it was found that the tract allotted to Ephraim was too small in proportion to its population and power.
jos 16:10they drave not out the Canaanites . . . but the Canaanites dwell among the Ephraimites unto this day, and serve under tribute--This is the first mention of the fatal policy of the Israelites, in neglecting the divine command (Deu 20:16) to exterminate the idolaters.